grass {agricolae}

Data for Friedman test

Description

Twelve homeowners are selected randomly to participate in an experiment with a plant nursery. Each homeowner is asked to select four fairly identical areas in his yard and to plant four different types of grasses, one in each area.

Usage

data(grass)

Format

A data frame with 48 observations on the following 3 variables.

judge

a numeric vector

trt

a factor with levels t1 t2 t3 t4

evaluation

a numeric vector

Details

Each of the 12 blocks consists of four fairly identical plots of land, each receiving care of approximately the same degree of skill because the four plots are presumably cared for by the same homeowern.

Source

Book: Practical Nonparametrics Statistics, pag 372.

References

Practical Nonparametrics Statistics. W.J. Conover, 1999

Examples

data(grass)
str(grass)